English to French Tech/Engineering Electronics / Elect Eng level gages

in "We offer a flipper/roller style indicator as an option to the tube/follower indicator. Flippers are industrial grade indicators, which consist of metal flags, silver on one side and red on the other. As the magnetic float moves up and down with the level, each flag will rotate 180° to show the other color."

Sadly, nothing about "rollers" in the text.